Regulating the charge transport ability of the TiO2/CsPbI2Br perovskite interface layer by MoS2 nanoparticles for high-performance carbon-based all-inorganic perovskite solar cells

Carbon-based all-inorganic perovskite solar cells (C-IPSCs) have garnered significant attention due to their more cost-effective manufacturing processes. In this study, we synthesize MoS₂ nanoparticles through electrochemical intercalation and incorporate them into the interface between the TiO₂ electron transport layer and the CsPbI₂Br perovskite film, serving as a buried interface modification layer. The pristine van der Waals interface and the elevated carrier mobility of MoS₂ nanoparticles can significantly enhance the efficiency of carrier transport and extraction at the interface. Additionally, this configuration optimizes the energy level alignment between the photoactive layer and the electron transport layer. More critically, MoS₂ nanoparticles facilitate the release of residual stress during annealing, thereby substantially improving the crystal quality of the perovskite film. This improvement further mitigates defect state formation, which in turn reduces non-radiative recombination of charge carriers. Due to the synergies mentioned above, C-IPSC achieves a champion power conversion efficiency (PCE) of 14.10 %. In addition, the device maintained 91 % of its initial PCE, demonstrating remarkable stability following 30 days of storage in an indoor environment at 25 °C and approximately 20 % relative humidity (RH).